The possible existence of any cause–effect relationships between the concentrations of organochlorines (OCs) and the presence of Morbillivirus and Toxoplasma gondii infections was investigated in both free-living and stranded specimens of Stenella coeruleoalba, Tursiops truncatus, Globicephala melas, Balaenoptera physalus and Physeter macrocephalus from the Mediterranean Sea. High blubber concentrations of polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT) were recorded in free-ranging G. melas. Tissue concentrations of PCBs and DDT in stranded T. truncatus (367 lipid weight (l.w.) and 143.7 mg/kg l.w., respectively) and S. coeruleoalba (139.9 l.w.; 92.9 mg/kg l.w.) were beyond the PCB threshold value for the appearance of adverse effects in marine mammals. Evidence of T. gondii infection was molecularly detected in three S. coeruleoalba and six T. truncatus.

Paramyxoviruses are responsible for a wide variety of diseases both in humans and in animals. Common to many paramyxoviruses is the fact that they can cause neurological symptoms in their final host. Newly discovered paramyxoviruses, such as the Hendra and Nipah viruses, show the same pattern of pathogenesis as that of the paramyxoviruses already known. Canine distemper virus (CDV) is a well-studied member of the genus Morbillivirus. Study of the neuropathogenesis of CDV might give insight into disease mechanisms and suggest approaches for the prevention of other recently discovered paramyxovirus infections.